1. Field of the Invention
The present invention relates to a polishing member and a method of manufacturing a semiconductor device, particularly, to a polishing member used in the manufacturing process of a semiconductor device and a method of manufacturing a semiconductor device including a planarizing treatment using the polishing member.
2. Description of the Related Art
In recent years, a marked progress has been achieved in the field of semiconductor devices in respect of the miniaturization of the device and the improvement in the element density, and intense research is being carried out in an attempt to further improve the fineness of the semiconductor device. Particularly, a CMP (Chemical Mechanical Polishing) technology is indispensable for forming, for example, a buried wiring (damascene wiring).
In the metal CMP technology that can be utilized for forming a buried wiring of a metal such as copper or aluminum, it is desirable to realize a high polishing rate and a high planarity and to suppress the scratch generation. Therefore, the polishing member used in the CMP treatment is required to be capable of holding the slurry, to be capable of following the warp of the wafer, and to have a suitable rigidity. Such being the situation, a polishing pad made of resin, for example, a closed-cell foamed resin or an open-cell foamed resin, is used mainly as the polishing member in the CMP treatment.
However, the polishing pad made of resin is hydrophobic. On the other hand, a major portion of the processing waste generated during the CMP treatment is also hydrophobic. What should be noted is that the hydrophobic processing waste is unlikely to be discharged to the outside promptly through the clearance between the polishing surface of the polishing pad and the polished surface of the semiconductor wafer. Unless the processing waste is promptly discharged to the outside through the clearance noted above, scratches are generated at a very high rate.
What should also be noted is that the hydrophobic processing waste tends to be attached easily to the polishing surface, with the result that the loading of the polishing pad is also generated at a high rate. If the polishing pad is loaded, the polishing rate and the planarity of the polished surface are markedly lowered, making it necessary to carry out a so-called “dressing”, in which the surface region of the pad is removed to regenerate the function of the pad, more frequently.